coggonobrien

So I went to pick up the kid's from day care tonight. Shut the truck off. Started it and went down the driveway. When I got to the end I hit the brakes and the peddle hit the floor but I did stop. I started pumping to see if I could hear/see fluid and the peddle got hard and was fine. I continued to sometimes have issues sometimes not on the way home (a couple miles of gravel between day care and home). I got in the yard and it was like the brakes were grabbing sometimes without me hitting the peddle. What are your thoughts? ABS light has been on for 2 years since I was dumb and forgot to install the ring in the rear end when I gear swapped. Will a regular scan too pull abs codes? How many ABS sensors are there and how do you clean them? O'reillys told me there's 1 on the rear end, 1 on each front corner, 1 on the transmission and 1 on the transfer case. I can't handle believe the transmission/transfer case. Is there a module that controls the whole thing or just the truck ecu?

Thanks!